The best alternatives to Fittr Pro are TracKit, Athos, and Workouts. If these 3 options don't work for you, we've listed a few more alternatives below.
TracKit lets you keep track of your body weight, workouts, vitamins, water intake, meditation, expenses, etc. Track numbers, habits, goals and time. Set goals and see how you progress towards them on a chart.
Workouts enables you to track your workout progress by date or grouped by week/month/year to make it easier to see your progress over time. It also offers a more visual way of displaying your workouts to further simplify comparing your weekly/monthly/yearly progress.